No abstract

Defects in insulin stimulation of blood flow have been suggested to contribute to insulin resistance. To directly test whether glucose uptake can be altered by changing blood flow, we infused bradykinin (27 g over 100 min), an endothelium-dependent vasodilator, into the femoral artery of 12 normal subjects (age 25 Ϯ 1 yr, body mass index 22 Ϯ 1 kg ր m 2 ) after an overnight fast ( n ϭ 5) and during normoglycemic hyperinsulinemic ( n ϭ 7) conditions (serum insulin 465 Ϯ 11 pmol ր liter, 0-100 min). Blood flow was measured simultaneously in both femoral regions using and PET. During hyperinsulinemia, muscle blood flow was 58% higher in the bradykinin-infused (38 Ϯ 9 ml ր kg muscle и min) than in the control leg (24 Ϯ 5, P Ͻ 0.01). Femoral muscle glucose uptake was identical in both legs (60.6 Ϯ 9.5 vs. 58.7 Ϯ 9.0 mol ր kg и min, bradykinin-infused vs. control leg, NS). Glucose extraction by skeletal muscle was 44% higher in the control (2.6 Ϯ 0.2 mmol ր liter) than the bradykinin-infused leg (1.8 Ϯ 0.2 mmol ր liter, P Ͻ 0.01). When bradykinin was infused in the basal state, flow was 98% higher in the bradykinin-infused (58 Ϯ 12 ml ր kg muscle и min) than the control leg (28 Ϯ 6 ml ր kg muscle и min, P Ͻ 0.01) but rates of muscle glucose uptake were identical in both legs (10.1 Ϯ 0.9 vs. 10.6 Ϯ 0.8 mol ր kg и min). We conclude that bradykinin increases skeletal muscle blood flow but not muscle glucose uptake in vivo. These data provide direct evidence against the hypothesis that blood flow is an independent regulator of insulin-stimulated glucose uptake in humans. ( J. Clin. Invest . 1996. 97:1741-1747.)

We evaluated the effect of 25 microg of fentanyl added to bupivacaine on sensory and motor block. By using a double-blinded study design, 80 men undergoing urologic surgery were randomized into the following four groups: Group I, bupivacaine 10 mg; Group II, bupivacaine 10 mg + fentanyl 25 microg; Group III, bupivacaine 7.5 mg + fentanyl 25 microg; Group IV, bupivacaine 5 mg + fentanyl 25 microg. The final volume of intrathecal injectate was adjusted to 2. 5 mL with sterile distilled water. Spinal anesthesia was administered with the 27-gauge Whitacre needle at the L2-3 interspace with the patient in the sitting position. Neural block was assessed by using pinprick and a modified Bromage scale. The degree of motor block was more profound in Group II compared with Group I at the end of operation. In Group IV, there was no motor block at the end of operation in any of the patients. The median level of the upper limit of the sensory block was higher than T(7) in all groups before the start of surgery. The addition of 25 microg of fentanyl to 5 mg of bupivacaine resulted in short-acting motor block. When 25 microg of fentanyl was added to 10 mg of bupivacaine, it increased the intensity and duration of motor block. Only 5 (6. 3%) of the patients needed supplemental analgesia during the operation. ¿abs¿

Premedication has been shown to affect both oxygen consumption and metabolic rate. We have compared the perioperative metabolic and haemodynamic effects of two alpha 2-agonists, clonidine and the more selective dexmedetomidine, in 30 ASA I patients undergoing plastic surgical procedures under general anaesthesia. Patients were premedicated with clonidine 4 micrograms kg-1 (n = 10), dexmedetomidine 2.5 micrograms kg-1 (n = 10) or saline (n = 10) i.m. The doses of clonidine and dexmedetomidine were intended to be equipotent. The maximum decrease in preoperative oxygen consumption was 8% and decreases in systolic and diastolic arterial pressures were 11% from baseline after clonidine and dexmedetomidine. During operation, the maximum reduction in heart rate was 18% in the clonidine and dexmedetomidine groups compared with the placebo group. After operation, the maximum decrease in systolic arterial pressure was 11%, diastolic arterial pressure 15% and oxygen consumption 17% in the clonidine and dexmedetomidine groups compared with placebo. In summary, both clonidine 4 micrograms kg-1 and dexmedetomidine 2.5 micrograms kg-1 decreased perioperative oxygen consumption effectively, with a similar haemodynamic profile.

Operating room (OR) is a cost-intensive environment, and it should be managed efficiently. When improving efficiency, shortening case duration by parallel processing, training of the resident surgeons, the choice of anesthetic methods, effective scheduling, and monitoring of the overall OR performance are important. When redesigning the OR processes, changes should be given a clear target and the achieved results monitored and reported to everyone involved. Advanced, reliable, and easy to use information technology solutions for OR management are under development. Pre-operative clinic and functionally designed facilities support efficiency. OR personnel must be kept motivated by clear management and leadership, supported by superiors.